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P0D65





Drive Motor Battery Cooling Blower Malfunction - DTC P0A81-P0A85, P0BC8-P0BCA, or P0D64-P0D66

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.

* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC P0A81
- Hybrid/EV Battery Pack Cooling Fan Control Circuit

DTC P0A84
- Hybrid/EV Battery Pack Cooling Fan Control Circuit Low Voltage

DTC P0A85
- Hybrid/EV Battery Pack Cooling Fan Control Circuit High Voltage

DTC P0BC8
- Hybrid/EV Battery Pack Cooling Fan Performance

DTC P0BC9
- Hybrid/EV Battery Pack Cooling Fan Feedback Circuit Low Voltage

DTC P0BCA
- Hybrid/EV Battery Pack Cooling Fan Feedback Circuit High Voltage

DTC P0D64
- Hybrid/EV Battery Pack Cooling Fan Enable Circuit

DTC P0D65
- Hybrid/EV Battery Pack Cooling Fan Enable Circuit Low Voltage

DTC P0D66
- Hybrid/EV Battery Pack Cooling Fan Enable Circuit High Voltage

Diagnostic Fault Information






Circuit/System Description

The hybrid/EV battery pack cooling fan draws air through the hybrid/EV battery pack to control the temperature of the hybrid/EV battery pack. To operate, the cooling fan receives an enable signal from the starter/generator control module. The enable control is controlled by a discrete high side driver in the starter/generator control module. When the enable control circuit is high, the fan will be enabled. The fan speed is
controlled by a fan control circuit from the starter/generator control module, by changing the duty cycle. Maximum fan speed is 3900 RPM. Hybrid/EV battery pack cooling fan enable circuit open and short to voltage diagnostics run continuously until hybrid/EV battery pack cooling fan is enabled to run while short to ground runs after it is enabled to run. These diagnostics detect and report a failure of the fan enable circuits.

Conditions for Running the DTC

P0A81, P0A84, or P0A85

* Ignition is RUN or CRANK

* The hybrid/EV battery pack cooling fan is enabled

P0BC8

* Ignition is RUN or CRANK

* The hybrid/EV battery pack cooling fan is enabled

* 12 V battery voltage is greater than 10 V

* The hybrid/EV battery pack cooling fan is commanded between 11-90%

* The hybrid/EV battery pack cooling fan enable delay timer is greater than 9 s

* DTC P0A84, P0A85, P0BC9, P0BCA, P0C32, P0D65, or P0D66 is not set

P0BC9 or P0BCA

* Ignition is RUN or CRANK

* The hybrid/EV battery pack cooling fan is enabled

* 12 V battery voltage is greater than 10 V

* The hybrid/EV battery pack cooling fan is commanded between 11-90%

* The hybrid/EV battery pack cooling fan enable delay timer is greater than 9 s

P0D64 or P0D66

* Ignition is RUN or CRANK

* The hybrid/EV battery pack cooling fan is not enabled

P0D65

* Ignition is RUN or CRANK

* The hybrid/EV battery pack cooling fan is enabled

Conditions for Setting the DTC

P0A81

An open is detected on the hybrid/EV battery pack cooling fan speed control circuit

P0A84

A short to ground is detected on the hybrid/EV battery pack cooling fan speed control circuit

P0A85

A short to voltage is detected on the hybrid/EV battery pack cooling fan speed control circuit

P0BC8

There is a excessive difference between the commanded hybrid/EV battery pack cooling fan speed and the hybrid/EV battery pack cooling fan speed feedback signal

P0BC9

The hybrid/EV battery pack cooling fan speed feedback signal is less than 8 Hz

P0BCA

The hybrid/EV battery pack cooling fan speed feedback signal is greater than 280 Hz

P0D64

An open is detected on the hybrid/EV battery pack cooling fan enable control circuit

P0D65

A short to ground is detected on the hybrid/EV battery pack cooling fan enable control circuit

P0D66

A short to voltage is detected on the hybrid/EV battery pack cooling fan enable control circuit

Action Taken When the DTC Sets

DTCs P0A81, P0A84, P0A85, P0BC8, P0BC9, P0BCA, P0D64, P0D65, and P0D66 are type B DTCs

Conditions for Clearing the DTC

DTCs P0A81, P0A84, P0A85, P0BC8, P0BC9, P0BCA, P0D64, P0D65, and P0D66 are type B DTCs

Reference Information

Schematic Reference

Hybrid/EV Cooling Schematics

Connector End View Reference

Component Connector End Views Sunshade - Left

Description and Operation

Hybrid Cooling System Description and Operation

Electrical Information Reference

* Circuit Testing Circuit Testing

* Connector Repairs Connector Repairs

* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections

* Wiring Repairs Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References Control Module References for scan tool information

Special Tools

EL-48900 - HEV Safety Kit

For equivalent regional tools, refer to Special Tools .

Circuit/System Verification

1. Verify the actual G14 Hybrid/EV Battery Pack Cooling Fan speed increases and decreases when commanding the Hybrid/EV Battery Pack Cooling Fan with a scan tool.

If the fan speed does not increase and decrease as commanded
Refer to Circuit/System Testing.

If the fan speed increases and decreases as commanded

2. Verify the scan tool Hybrid Powertrain Control Module 14V Power Module Fan Speed parameter increases and decreases when commanding the Hybrid/EV Battery Pack Cooling Fan with a scan tool.

If the parameter does not increase and decrease as commanded
Refer to Circuit/System Testing.

If the parameter increases and decreases as commanded

3. All OK.

Circuit/System Testing

Danger: Always perform the High Voltage Disabling procedure prior to servicing any High Voltage component or connection. Personal Protection Equipment (PPE) and proper procedures must be followed.


The High Voltage Disabling procedure includes the following steps:


* Identify how to disable high voltage.


* Identify how to test for the presence of high voltage.


* Identify condition under which high voltage is always present and personal protection equipment (PPE) and proper procedures must be followed.


Before working on any high voltage system, be sure to wear the following Personal Protection Equipment:


* Safety glasses with appropriate side shields when within 15 meters (50 feet) of the vehicle, either indoors or outdoors.


* Certified and up-to-date Class "0" Insulation gloves rated at 1000V with leather protectors.


- Visually and functionally inspect the gloves before use.


- Wear the Insulation gloves with leather protectors at all times when working with the high voltage battery assembly, whether the system is energized or not.


Failure to follow the procedures may result in serious injury or death.


Danger: The eAssist battery pack assembly will utilize an exchange program. Please consult the most recent revision of bulletin/PI# PIC5520, available in Service Information (SI), for a list of approved eAssist battery pack assembly service procedures. Components that may be removed and serviced without exchanging the complete battery pack assembly are identified in the bulletin/PI. Please contact the GM Technical Assistance Center (1-877-446-8227) if you have any questions.


1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the G14 Hybrid/EV Battery Pack Cooling Fan. It may take up to 2 min for all vehicle systems to power down.

2. Test for less than 10 ohms between the ground circuit terminal 1 and ground.

If 10 ohms or greater

1. Ignition OFF.

2. Test for less than 2 ohms between the ground circuit terminal 1 and ground.

If 2 ohms or greater, repair the open/high resistance in the circuit.

If less than 2 ohms, repair the open/high resistance in the ground connection.

If less than 10 ohms

3. Ignition ON.

4. Verify a test lamp illuminates between the B+ circuit terminal 5 and ground.

If the test lamp does not illuminate and the circuit fuse is good

1. Ignition OFF.

2. Test for less than 2 ohms in the B+ circuit end to end.

If 2 ohms or greater, repair the open/high resistance in the circuit.

If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse.

If the test lamp does not illuminate and the circuit fuse is open

1. Ignition OFF.

2. Test for infinite resistance between the B+ circuit and ground.

If less than infinite resistance, repair the short to ground on the circuit.

If infinite resistance, replace the G14 Hybrid/EV Battery Pack Cooling Fan.

If the test lamp illuminates

5. Connect a test lamp between the control circuit terminal 4 and ground.

6. Verify the test lamp turns ON when commanding the Hybrid/EV Battery Pack Cooling Fan with a scan tool and OFF when releasing the control.

If the test lamp is always OFF

1. Ignition OFF, disconnect the X3 harness connector at the K59 Starter/Generator Control Module.

2. Test for infinite resistance between the control circuit and ground.

If less than infinite resistance, repair the short to ground on the circuit.

If infinite resistance

3. . Test for less than 2 ohms in the control circuit end to end.

If 2 ohms or greater, repair the open/high resistance in the circuit

If less than 2 ohms, replace the K59 Starter/Generator Control Module.

If the test lamp is always ON

1. Ignition OFF, disconnect the X3 harness connector at the K59 Starter/Generator Control Module.

2. Test for less than 1 V between the control circuit and ground.

If 1 V or greater, test the control circuit for a short to voltage.

If less than 1 V, replace the K59 Starter/Generator Control Module.

If the test lamp turns ON and OFF

7. Test for 4.8-5.2 V between the signal circuit terminal 2 and ground.

If less than 4.8 V

1. Ignition OFF, disconnect the X3 harness connector at the K59 Starter/Generator Control Module.

2. Test for infinite resistance between the signal circuit and ground.

If less than infinite resistance, repair the short to ground on the circuit.

If infinite resistance

3. . Test for less than 2 ohms in the signal circuit end to end.

If 2 ohms or greater, repair the open/high resistance in the circuit

If less than 2 ohms, replace the K59 Starter/Generator Control Module.

If greater than 5.2 V

1. Ignition OFF, disconnect the X3 harness connector at the K59 Starter/Generator Control Module.

2. Test for less than 1 V between the signal circuit and ground.

If 1 V or greater, test the signal circuit for a short to voltage.

If less than 1 V, replace the K59 Starter/Generator Control Module.

If between 4.8-5.2 V

8. Connect a 3 A fused jumper wire to the signal circuit terminal 2.

9. Verify the scan tool Hybrid Powertrain Control Module 14V Power Module Fan Speed parameter is greater than 0 RPM while rapidly tapping the jumper wire to ground.

If 0 RPM
Replace the K59 Starter/Generator Control Module

If greater than 0 RPM

10. Connect a test lamp between the signal circuit terminal 3 and B+.

11. Verify the test lamp becomes progressively dimmer as the fan speed is increased and progressively brighter as the fan speed is decreased when commanding the Hybrid/EV Battery Pack Cooling Fan with a scan tool.

If the test lamp does not illuminate

1. Ignition OFF, disconnect the X3 harness connector at the K59 Starter/Generator Control Module.

2. Test for less than 1 V between the signal circuit and ground.

If 1 V or greater, test the signal circuit for a short to voltage.

If less than 1 V

3. Test for less than 2 ohms in the signal circuit end to end.

If 2 ohms or greater, repair the open/high resistance in the circuit

If less than 2 ohms, replace the K59 Starter/Generator Control Module.

If the test lamp illuminates, but does not change in brightness

1. Ignition OFF, disconnect the X3 harness connector at the K59 Starter/Generator Control Module.

2. Test for infinite resistance between the signal circuit and ground.

If less than infinite resistance, repair the short to ground on the circuit.

If infinite resistance, replace the K59 Starter/Generator Control Module.

If the test lamp brightness changes as commanded

12. Test or replace the G14 Hybrid/EV Battery Pack Cooling Fan.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the repair.

* Drive Motor Battery Cooling Blower Replacement

* Control Module References Control Module References for starter/generator control module replacement, programming, and setup.